Plastic pump, and method for manufacturing same

ABSTRACT

The present invention relates to a plastic pump and to a method for manufacturing same. The method includes: a pre-manufacturing step for pre-manufacturing an inner body and impeller formed from a fluorine resin material by means of injection molding; a body manufacturing step for manufacturing a complete body, in which the inner body is formed from a fluorine resin and the outer body is formed from a plastic material, by molding the plastic material in a first mold after fixing the pre-manufactured inner body to the first mold; a cover manufacturing step for manufacturing an impeller cover, which is formed from a plastic material, by molding the plastic material in a second mold so as to protect the manufactured impeller; and a finishing step for completing the plastic pump by sequentially assembling the manufactured complete body, the impeller, and the impeller cover. According to the present invention, only a fluid transporting path is lined with the fluorine resin and is thus not easily deformed by temperature regardless of the type of fluid and is resistant to a chemical reaction with a fluid for improved product quality and significant extension of the period over which the pump can be used.

TECHNICAL FIELD

The present invention relates to a plastic pump, and a method formanufacturing the same, and in particular to a plastic pump, and amethod for manufacturing the same wherein a fluid transporting path ofthe inside of a plastic pump is lined with a fluorine resin, so theplastic pump will not be easily deformed by temperature based on thekinds of fluids, and the plastic pump is strong to any chemical reactionwith fluid.

BACKGROUND ART

In recent years, a plastic pump the weight of which is lighter than asteel product is being used more and more thanks to the benefitsresulting from is the decreased weight of the pump. In such a plasticpump, since a pump itself is made of a plastic material (PP, GFFRP), afluid transporting path formed in the inside is also made of only aplastic material.

If the fluid transporting path is made of only a plastic material, theinside of the fluid transporting path may be easily deformed by thetemperature based on the kinds (characteristics) of the fluid flowingthrough the fluid transporting path or may have a problem due to achemical reaction with the fluid. In order to prevent such a problem,the whole materials of the plastic pump may be made of a fluorinematerial, but in this case the manufacturing costs a lot.

DISCLOSURE OF INVENTION

Accordingly, the present invention is made in an effort to resolve theabove problems. It is an object of the present invention to provide aplastic pump and a method for manufacturing the same wherein only thefluid transporting path formed inside the plastic pump is lined with afluorine resin, so the plastic pump is not easily deformed bytemperature irrespective of the kinds of the fluids, and the plasticpump is strong to any chemical reaction with fluid.

To achieve the above objects, there is provided a method formanufacturing a plastic pump, which may include, but is not limited to apre-manufacturing step wherein an inner body made of a fluorine resinmaterial and forming a fluid transporting path and an impeller engagedto the inner body are previously manufactured through an injection moldmethod; a body manufacturing step wherein for manufacturing a completebody, in which the inner body is formed from a fluorine resin and theouter body is formed from a plastic material, by molding the plasticmaterial in a first mold after fixing the pre-manufactured inner body tothe first mold; a cover manufacturing step wherein for manufacturingimpeller cover, which is formed a plastic material, by molding theplastic material in a second mold so as to protect the manufacturedimpeller; and a finishing step wherein for completing a plastic pump bysequentially assembling the manufactured complete body, the impeller andthe impeller cover.

In addition, according to the method for manufacturing a plastic pumpaccording to an exemplary embodiment of the present invention, thefluorine resin is formed of PFA or PVDF, and the plastic material isformed of PP, PVC or PPS.

In addition, according to the method for manufacturing a plastic pumpaccording to an exemplary embodiment of the present invention, duringthe injection mold method with respect to the inner body and theimpeller, a PFA, which is a fluorine resin material is injected in theinjection mold at a pressure of is 35˜80 kgf/cm².

In addition, according to the method for manufacturing a plastic pumpaccording to an exemplary embodiment of the present invention, the PFA,which is the fluorine resin material, has a temperature of 270° C.˜420°C.

In addition, according to the method for manufacturing a plastic pumpaccording to an exemplary embodiment of the present invention, the PVDF,which is the fluorine resin material, has a temperature of 170° C.˜235°C.

In addition, according to the method for manufacturing a plastic pumpaccording to an exemplary embodiment of the present invention, whenmold-injecting the plastic material in the first mold, the injection isperformed at a pressure of 35˜80 kgf/cm².

In addition, according to the method for manufacturing a plastic pumpaccording to an exemplary embodiment of the present invention, the innerbody formed of the fluorine resin(PFA or PVDF) material has a thicknessof 1˜10 mm.

In addition, the present invention is directed to a plastic pump whichis manufactured by the above method for manufacturing a plastic pump.

ADVANTAGEOUS EFFECTS

In the plastic pump manufactured according to the plastic pump and isthe method for manufacturing the same according to the presentinvention, only the fluid transporting path is lined with a fluorineresin, so the plastic pump is not easily deformed by temperatureregardless of the type of the fluids, and is resistant to a chemicalreaction with a fluid for improved product quality and significantextension of the period over which the pump can be used.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic view illustrating a configuration of a plasticpump to an exemplary embodiment of the present invention may apply.

FIG. 2 is a step view for describing a manufacturing procedure of aplastic pump according to the present invention.

FIG. 3 is a view illustrating an inner body formed of a fluorine resinaccording to an exemplary embodiment of the present invention.

FIG. 4 is an example view illustrating an outer body formed by injectinga plastic material in a first mold according to an exemplary embodimentof the present invention.

FIG. 5 is an example view illustrating a plastic pump assembled in afinishing step according to an exemplary embodiment of the presentinvention.

BEST MODES FOR CARRYING OUT THE INVENTION

The most preferred embodiments of the present invention will bedescribed with reference to the accompanying drawings to the extent thata person having ordinary skill in the art can easily implement.Throughout the description of the present invention, the same componentswill be given the same reference numbers, and duplicating descriptionsmay be omitted.

Hereinafter, the manufacturing procedures according to an exemplaryembodiment of the present invention will be described in details withreference to FIGS. 1 to 5.

FIG. 1 is a schematic view illustrating a configuration of a plasticpump to an exemplary embodiment of the present invention may apply. FIG.2 is a step view for describing a manufacturing procedure of a plasticpump according to the present invention. FIG. 3 is a view illustratingan inner body formed of a fluorine resin according to an exemplaryembodiment of the present invention. FIG. 4 is an example viewillustrating an outer body formed by injecting a plastic material in afirst mold according to an exemplary embodiment of the presentinvention. FIG. 5 is an example view illustrating a plastic pumpassembled in a finishing step according to an exemplary embodiment ofthe present invention.

Referring to FIGS. 1 and 2, the plastic pump 10 according to the presentinvention may include, but is not limited to, an inner body 20, an outerbody 30, an impeller 40 and an impeller cover 50.

The inner body 20 and the impeller 40 are previously made of a fluorineresin (PFA or PVDF) material through an injection mold method (S100).When the inner body 20 and the impeller 40 are made by the injectionmold method, the PFA (PVDF), which is a fluorine resin material, isinjected at a pressure of 35˜80 kgf/cm² in the injection mold.

At this time, the PFA, which is a fluorine resin material, has atemperature of 270° C.˜420° C., and the PVDF, which is a fluorine resinmaterial, has a temperature of 170° C.˜235° C. In addition, it ispreferred that the inner body 20 made of a fluorine resin (PFA or PVDF)material has a thickness of 1˜10 mm. An example of the configuration ofthe inner body 20 is illustrated in FIG. 3. In the inner body 20, afluid transporting path 20 a is formed of a fluorine resin. For this,even if chemical liquid flows through the fluid transporting path 20 a,the inner surface of the inner body 20, namely, the inner surface of thefluid transporting path 20 a does not go corroded and is chemicallysafe, thus improving the quality of the product.

Thereafter, the inner body 20 previously manufactured in the step S100is fixed at a first mold (not illustrated) (S200), and a plasticmaterial (PP or PVC or PPS) is injected in the first mold, so thecomplete body is manufactured, is wherein the inner body 20 is made of afluorine resin, and the outer body 30 is made of a plastic material(S300). During the injection mold, the plastic material is injected inthe first mold at a pressure of 35˜80 kgf/cm².

In case where the inner body 20 is made of PFA, the outer body 30 may beformed of PP, PVC or PPS, but in case where the inner body 20 is made ofPVDF, it is preferred that the outer body 30 is formed of PP or PVC.

In order to protect the manufactured impeller 40, the plastic material(PP or PVC or PPS) is injected in the second mold (not illustrated),thus manufacturing an impeller cover 50 made of a plastic material(S400).

Thereafter, the manufactured whole bodies 20 and 30, the impeller 40 andthe impeller cover 50 are sequentially assembled, and the plastic pump10 is finished (S500).

At this time, since the injection is performed in the inner body 20, andthen the outer body 30 is manufactured, the procedure for assembling theinner body and the outer body can be omitted in the following procedure.

The present invention made by the inventor has been described so far indetails based on the exemplary embodiments, but the present invention isnot limited thereto. Various modifications are available withoutdeparting from the scope of the present invention.

1. A method for manufacturing a plastic pump, comprising: a premanufacturing step wherein an inner body made of a fluorine resinmaterial and forming a fluid transporting path and an impeller engagedto the inner body are previously manufactured through an injection moldmethod; a body manufacturing step wherein for manufacturing a completebody, in which the inner body is formed from a fluorine resin and theouter body is formed from a plastic material, by molding the plasticmaterial in a first mold after fixing the pre-manufactured inner body tothe first mold; a cover manufacturing step wherein for manufacturingimpeller cover, which is formed a plastic material, by molding theplastic material in a second mold so as to protect the manufacturedimpeller; and a finishing step wherein for completing a plastic pump bysequentially assembling the manufactured complete body, the impeller andthe impeller cover.
 2. The method of claim 1, wherein the fluorine resinis formed of PFA or PVDF, and the plastic material is formed of PP, PVCor PPS.
 3. The method of claim 2, wherein during the injection moldmethod with respect to the inner body and the impeller, a PFA, which isa fluorine resin material is injected in the injection mold at apressure of 35˜80 kgf/cm2.
 4. The method of claim 3, wherein the PFA,which is the fluorine resin material, has a temperature of 270° C.˜420°C.
 5. The method of claim 2, wherein the PVDF, which is the fluorineresin material, has a temperature of 170° C.˜235° C.
 6. The method ofclaim 2, wherein when mold-injecting the plastic material in the firstmold, the injection is performed at a pressure of 35˜80 kgf/cm2.
 7. Themethod of claim 2, wherein the inner body formed of the fluorine resinmaterial has a thickness of 1˜10 mm.
 8. A plastic pump which ismanufactured by a manufacturing method of claim
 1. 9. A plastic pumpwhich is manufactured by a manufacturing method of claim
 2. 10. Aplastic pump which is manufactured by a manufacturing method of claim 3.11. A plastic pump which is manufactured by a manufacturing method ofclaim
 4. 12. A plastic pump which is manufactured by a manufacturingmethod of claim
 5. 13. A plastic pump which is manufactured by amanufacturing method of claim
 6. 14. A plastic pump which ismanufactured by a manufacturing method of claim 7.